To get started add a Beat Machine from the Common category. Then add a Program Sheet and perhaps a Marble machine or two. The Program Sheet is where you will edit the song's "score".

The Beat Machine needs to be connected to the Program Sheet to trigger reading of rows on the sheet. Click the Beat Machine you placed and notice the 3 buttons in the pop-up. Click on one and you will see a line. Now move the mouse over the Program Sheet device and click to connect. Similarly you can connect the Program Sheet's signal outputs to the Marble Machine or other Devices.

In the Program Sheet's pop-up you click or drag over the cells to mark the ones which will generate a signal when the row is read.

Now place a Snare Drum, from the Percussive category, somewhere below the Marble Machine and press Play to see what happens.

Settings

Besides the common options like sound volume and screen resolution you will note a Sound Data drop-down. This allows you to select which Sound Font to use. A Sound Font tells the game what an instrument sounds like and the sound can differ quite a bit depending on which Sound Font you use. Some might sound quite realistic while others sound very synthetic.

Just do a search for Sound Fonts on the internet or visit http://www.synthfont.com/links_to_soundfonts.html for some links. Copy the SF2 file into the game's .\muchine_Data\StreamingAssets\SoundData\ folder and restart the game to see the new Sound Font in the settings.